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# Copyright (C) 2008-2012 AG Projects. See LICENSE for details
import random
import re
from collections import deque, namedtuple
from application.system import host as host_module
from twisted.internet.protocol import connectionDone
from twisted.protocols.basic import LineReceiver
from msrplib import MSRPError
class ParsingError(MSRPError):
pass
class HeaderParsingError(ParsingError):
def __init__(self, header, reason):
self.header = header
ParsingError.__init__(self, 'Error parsing {} header: {}'.format(header, reason))
# Header value data types (for decoded values)
#
ByteRange = namedtuple('ByteRange', ['start', 'end', 'total'])
Status = namedtuple('Status', ['code', 'comment'])
ContentDisposition = namedtuple('ContentDisposition', ['disposition', 'parameters'])
# Header value types (describe how to encode/decode the value)
#
class SimpleHeaderType(object):
data_type = object
@staticmethod
def decode(encoded):
return encoded
@staticmethod
def encode(decoded):
return decoded
class UTF8HeaderType(object):
data_type = unicode
@staticmethod
def decode(encoded):
return encoded.decode('utf-8')
@staticmethod
def encode(decoded):
return decoded.encode('utf-8')
class URIHeaderType(object):
data_type = deque
@staticmethod
def decode(encoded):
return deque(parse_uri(uri) for uri in encoded.split(' '))
@staticmethod
def encode(decoded):
return ' '.join(str(uri) for uri in decoded)
class IntegerHeaderType(object):
data_type = int
@staticmethod
def decode(encoded):
return int(encoded)
@staticmethod
def encode(decoded):
return str(decoded)
class LimitedChoiceHeaderType(SimpleHeaderType):
allowed_values = frozenset()
@classmethod
def decode(cls, encoded):
if encoded not in cls.allowed_values:
raise ValueError('Invalid value: {!r}'.format(encoded))
return encoded
class SuccessReportHeaderType(LimitedChoiceHeaderType):
allowed_values = frozenset({'yes', 'no'})
class FailureReportHeaderType(LimitedChoiceHeaderType):
allowed_values = frozenset({'yes', 'no', 'partial'})
class ByteRangeHeaderType(object):
data_type = ByteRange
regex = re.compile(r'(?P<start>\d+)-(?P<end>\*|\d+)/(?P<total>\*|\d+)')
@classmethod
def decode(cls, encoded):
match = cls.regex.match(encoded)
if match is None:
raise ValueError('Invalid byte range value: {!r}'.format(encoded))
start, end, total = match.groups()
start = int(start)
end = int(end) if end != '*' else None
total = int(total) if total != '*' else None
return ByteRange(start, end, total)
@staticmethod
def encode(decoded):
start, end, total = decoded
return '{}-{}/{}'.format(start, end or '*', total or '*')
class StatusHeaderType(object):
data_type = Status
@staticmethod
def decode(encoded):
namespace, sep, rest = encoded.partition(' ')
if namespace != '000' or sep != ' ':
raise ValueError('Invalid status value: {!r}'.format(encoded))
code, _, comment = rest.partition(' ')
if not code.isdigit() or len(code) != 3:
raise ValueError('Invalid status code: {!r}'.format(code))
return Status(int(code), comment or None)
@staticmethod
def encode(decoded):
code, comment = decoded
if comment is None:
return '000 {:03d}'.format(code)
else:
return '000 {:03d} {}'.format(code, comment)
class ContentDispositionHeaderType(object):
data_type = ContentDisposition
regex = re.compile(r'(\w+)=("[^"]+"|[^";]+)')
@classmethod
def decode(cls, encoded):
disposition, _, parameters = encoded.partition(';')
if not disposition:
raise ValueError('Invalid content disposition: {!r}'.format(encoded))
return ContentDisposition(disposition, {name: value.strip('"') for name, value in cls.regex.findall(parameters)})
@staticmethod
def encode(decoded):
disposition, parameters = decoded
return '; '.join([disposition] + ['{}="{}"'.format(name, value) for name, value in parameters.iteritems()])
class ParameterListHeaderType(object):
data_type = dict
regex = re.compile(r'(\w+)=("[^"]+"|[^",]+)')
@classmethod
def decode(cls, encoded):
return {name: value.strip('"') for name, value in cls.regex.findall(encoded)}
@staticmethod
def encode(decoded):
return ', '.join('{}="{}"'.format(name, value) for name, value in decoded.iteritems())
class DigestHeaderType(ParameterListHeaderType):
@classmethod
def decode(cls, encoded):
algorithm, sep, parameters = encoded.partition(' ')
if algorithm != 'Digest' or sep != ' ':
raise ValueError('Invalid Digest header value')
return super(DigestHeaderType, cls).decode(parameters)
@staticmethod
def encode(decoded):
return 'Digest ' + super(DigestHeaderType, DigestHeaderType).encode(decoded)
# Header classes
#
class MSRPHeaderMeta(type):
__classmap__ = {}
name = None
def __init__(cls, name, bases, dictionary):
type.__init__(cls, name, bases, dictionary)
if cls.name is not None:
cls.__classmap__[cls.name] = cls
def __call__(cls, *args, **kw):
if cls.name is not None:
return super(MSRPHeaderMeta, cls).__call__(*args, **kw) # specialized class, instantiated directly.
else:
return cls._instantiate_specialized_class(*args, **kw) # non-specialized class, instantiated as a more specialized class if available.
def _instantiate_specialized_class(cls, name, value):
if name in cls.__classmap__:
return super(MSRPHeaderMeta, cls.__classmap__[name]).__call__(value)
else:
return super(MSRPHeaderMeta, cls).__call__(name, value)
class MSRPHeader(object):
__metaclass__ = MSRPHeaderMeta
name = None
type = SimpleHeaderType
def __init__(self, name, value):
self.name = name
if isinstance(value, str):
self.encoded = value
else:
self.decoded = value
def __eq__(self, other):
if isinstance(other, MSRPHeader):
return self.name == other.name and self.decoded == other.decoded
return NotImplemented
def __ne__(self, other):
return not self == other
@property
def encoded(self):
if self._encoded is None:
self._encoded = self.type.encode(self._decoded)
return self._encoded
@encoded.setter
def encoded(self, encoded):
self._encoded = encoded
self._decoded = None
@property
def decoded(self):
if self._decoded is None:
try:
self._decoded = self.type.decode(self._encoded)
except Exception as e:
raise HeaderParsingError(self.name, str(e))
return self._decoded
@decoded.setter
def decoded(self, decoded):
if not isinstance(decoded, self.type.data_type):
try:
# noinspection PyArgumentList
decoded = self.type.data_type(decoded)
except Exception:
raise TypeError('value must be an instance of {}'.format(self.type.data_type.__name__))
self._decoded = decoded
self._encoded = None
class MSRPNamedHeader(MSRPHeader):
def __init__(self, value):
MSRPHeader.__init__(self, self.name, value)
class ToPathHeader(MSRPNamedHeader):
name = 'To-Path'
type = URIHeaderType
class FromPathHeader(MSRPNamedHeader):
name = 'From-Path'
type = URIHeaderType
class MessageIDHeader(MSRPNamedHeader):
name = 'Message-ID'
type = SimpleHeaderType
class SuccessReportHeader(MSRPNamedHeader):
name = 'Success-Report'
type = SuccessReportHeaderType
class FailureReportHeader(MSRPNamedHeader):
name = 'Failure-Report'
type = FailureReportHeaderType
class ByteRangeHeader(MSRPNamedHeader):
name = 'Byte-Range'
type = ByteRangeHeaderType
@property
def start(self):
return self.decoded.start
@property
def end(self):
return self.decoded.end
@property
def total(self):
return self.decoded.total
class StatusHeader(MSRPNamedHeader):
name = 'Status'
type = StatusHeaderType
@property
def code(self):
return self.decoded.code
@property
def comment(self):
return self.decoded.comment
class ExpiresHeader(MSRPNamedHeader):
name = 'Expires'
type = IntegerHeaderType
class MinExpiresHeader(MSRPNamedHeader):
name = 'Min-Expires'
type = IntegerHeaderType
class MaxExpiresHeader(MSRPNamedHeader):
name = 'Max-Expires'
type = IntegerHeaderType
class UsePathHeader(MSRPNamedHeader):
name = 'Use-Path'
type = URIHeaderType
class WWWAuthenticateHeader(MSRPNamedHeader):
name = 'WWW-Authenticate'
type = DigestHeaderType
class AuthorizationHeader(MSRPNamedHeader):
name = 'Authorization'
type = DigestHeaderType
class AuthenticationInfoHeader(MSRPNamedHeader):
name = 'Authentication-Info'
type = ParameterListHeaderType
class ContentTypeHeader(MSRPNamedHeader):
name = 'Content-Type'
type = SimpleHeaderType
class ContentIDHeader(MSRPNamedHeader):
name = 'Content-ID'
type = SimpleHeaderType
class ContentDescriptionHeader(MSRPNamedHeader):
name = 'Content-Description'
type = SimpleHeaderType
class ContentDispositionHeader(MSRPNamedHeader):
name = 'Content-Disposition'
type = ContentDispositionHeaderType
class UseNicknameHeader(MSRPNamedHeader):
name = 'Use-Nickname'
type = UTF8HeaderType
class HeaderOrderMapping(dict):
__levels__ = {
0: ['To-Path'],
1: ['From-Path'],
2: ['Status', 'Message-ID', 'Byte-Range', 'Success-Report', 'Failure-Report'] +
['Authorization', 'Authentication-Info', 'WWW-Authenticate', 'Expires', 'Min-Expires', 'Max-Expires', 'Use-Path', 'Use-Nickname'],
3: ['Content-ID', 'Content-Description', 'Content-Disposition'],
4: ['Content-Type']
}
def __init__(self):
super(HeaderOrderMapping, self).__init__({name: level for level, name_list in self.__levels__.items() for name in name_list})
def __missing__(self, key):
return 3 if key.startswith('Content-') else 2
sort_key = dict.__getitem__
class HeaderOrdering(object):
name_map = HeaderOrderMapping()
sort_key = name_map.sort_key
class MissingHeader(object):
decoded = None
class MSRPData(object):
def __init__(self, transaction_id, method=None, code=None, comment=None, headers=None, data='', contflag='$'):
if method is None and code is None:
raise ValueError('either method or code must be specified')
elif method is not None and code is not None:
raise ValueError('method and code cannot be both specified')
elif code is None and comment is not None:
raise ValueError('comment should only be specified when code is specified')
self.transaction_id = transaction_id
self.method = method
self.code = code
self.comment = comment
self.headers = headers or {}
self.data = data
self.contflag = contflag
if method is not None:
self._first_line = 'MSRP {} {}'.format(transaction_id, method)
elif comment is None:
self._first_line = 'MSRP {} {:03d}'.format(transaction_id, code)
else:
self._first_line = 'MSRP {} {:03d} {}'.format(transaction_id, code, comment)
def copy(self):
return self.__class__(self.transaction_id, self.method, self.code, self.comment, self.headers.copy(), self.data, self.contflag)
def __setattr__(self, name, value):
if name in {'method', 'code', 'comment'} and name in self.__dict__:
raise AttributeError('Cannot overwrite attribute')
if name == 'transaction_id' and name in self.__dict__:
self._first_line = self._first_line.replace(self.transaction_id, value)
super(MSRPData, self).__setattr__(name, value)
def __str__(self): # TODO: make __str__ == encode()?
return self._first_line
def __repr__(self):
description = self._first_line
for name in sorted(self.headers, key=HeaderOrdering.sort_key):
description += ' {}={!r}'.format(name, self.headers[name].encoded)
description += ' len={}'.format(self.size)
return '<{} at {:#x} {} {}>'.format(self.__class__.__name__, id(self), description, self.contflag)
def __eq__(self, other):
if isinstance(other, MSRPData):
return self._first_line == other._first_line and self.headers == other.headers and self.data == other.data and self.contflag == other.contflag
return NotImplemented
def __ne__(self, other):
return not self == other
def add_header(self, header):
self.headers[header.name] = header
def verify_headers(self):
if 'To-Path' not in self.headers:
raise HeaderParsingError('To-Path', 'header is missing')
if 'From-Path' not in self.headers:
raise HeaderParsingError('From-Path', 'header is missing')
for header in self.headers.itervalues():
_ = header.decoded
@property
def from_path(self):
return self.headers.get('From-Path', MissingHeader).decoded
@property
def to_path(self):
return self.headers.get('To-Path', MissingHeader).decoded
@property
def content_type(self):
return self.headers.get('Content-Type', MissingHeader).decoded
@property
def message_id(self):
return self.headers.get('Message-ID', MissingHeader).decoded
@property
def byte_range(self):
return self.headers.get('Byte-Range', MissingHeader).decoded
@property
def status(self):
return self.headers.get('Status', MissingHeader).decoded
@property
def failure_report(self):
return self.headers.get('Failure-Report', MissingHeader).decoded or 'yes'
@property
def success_report(self):
return self.headers.get('Success-Report', MissingHeader).decoded or 'no'
@property
def size(self):
return len(self.data)
def encode_start(self):
lines = [self._first_line] + ['{}: {}'.format(name, self.headers[name].encoded) for name in sorted(self.headers, key=HeaderOrdering.sort_key)]
if 'Content-Type' in self.headers:
lines.append('\r\n')
return '\r\n'.join(lines)
def encode_end(self, continuation):
return '\r\n-------%s%s\r\n' % (self.transaction_id, continuation)
def encode(self):
return self.encode_start() + self.data + self.encode_end(self.contflag)
class MSRPProtocol(LineReceiver):
MAX_LENGTH = 16384
MAX_LINES = 64
def __init__(self, msrp_transport):
self.msrp_transport = msrp_transport
self.term_buf = ''
self.term_re = None
self.term_substrings = []
self._reset()
def _reset(self):
self._chunk_header = ''
self.data = None
self.line_count = 0
def connectionMade(self):
self.msrp_transport._got_transport(self.transport)
def lineReceived(self, line):
if self.data:
if len(line) == 0:
terminator = '\r\n-------' + self.data.transaction_id
continue_flags = [c+'\r\n' for c in '$#+']
self.term_buf = ''
self.term_re = re.compile("^(.*)%s([$#+])\r\n(.*)$" % re.escape(terminator), re.DOTALL)
self.term_substrings = [terminator[:i] for i in xrange(1, len(terminator)+1)] + [terminator+cont[:i] for cont in continue_flags for i in xrange(1, len(cont))]
self.term_substrings.reverse()
self.msrp_transport.logger.received_new_chunk(self._chunk_header+self.delimiter, self.msrp_transport, chunk=self.data)
self.msrp_transport._data_start(self.data)
self.setRawMode()
else:
match = self.term_re.match(line)
if match:
continuation = match.group(1)
self.msrp_transport.logger.received_new_chunk(self._chunk_header, self.msrp_transport, chunk=self.data)
self.msrp_transport.logger.received_chunk_end(line+self.delimiter, self.msrp_transport, transaction_id=self.data.transaction_id)
self.msrp_transport._data_start(self.data)
self.msrp_transport._data_end(continuation)
self._reset()
# This line is only here because it allows the subclass MSRPPRotocol_withLogging
# to know that the packet ended. In need of redesign. -Luci
self.setLineMode('')
else:
self._chunk_header += line+self.delimiter
self.line_count += 1
if self.line_count > self.MAX_LINES:
self.msrp_transport.logger.received_illegal_data(self._chunk_header, self.msrp_transport)
self._reset()
return
try:
name, value = line.split(': ', 1)
except ValueError:
return # let this pass silently, we'll just not read this line
else:
self.data.add_header(MSRPHeader(name, value))
else: # we received a new message
try:
msrp, transaction_id, rest = line.split(" ", 2)
except ValueError:
self.msrp_transport.logger.received_illegal_data(line+self.delimiter, self.msrp_transport)
return # drop connection?
if msrp != "MSRP":
self.msrp_transport.logger.received_illegal_data(line+self.delimiter, self.msrp_transport)
return # drop connection?
method, code, comment = None, None, None
rest_sp = rest.split(" ", 1)
try:
if len(rest_sp[0]) != 3:
raise ValueError
code = int(rest_sp[0])
except ValueError: # we have a request
method = rest_sp[0]
else: # we have a response
if len(rest_sp) > 1:
comment = rest_sp[1]
self.data = MSRPData(transaction_id, method, code, comment)
self.term_re = re.compile("^-------%s([$#+])$" % re.escape(transaction_id))
self._chunk_header = line+self.delimiter
def lineLengthExceeded(self, line):
self._reset()
def rawDataReceived(self, data):
data = self.term_buf + data
match = self.term_re.match(data)
if match: # we got the last data for this message
contents, continuation, extra = match.groups()
if contents:
self.msrp_transport.logger.received_chunk_data(contents, self.msrp_transport, transaction_id=self.data.transaction_id)
self.msrp_transport._data_write(contents, final=True)
self.msrp_transport.logger.received_chunk_end('\r\n-------%s%s\r\n' % (self.data.transaction_id, continuation), self.msrp_transport, transaction_id=self.data.transaction_id)
self.msrp_transport._data_end(continuation)
self._reset()
self.setLineMode(extra)
else:
for term in self.term_substrings:
if data.endswith(term):
self.term_buf = data[-len(term):]
data = data[:-len(term)]
break
else:
self.term_buf = ''
self.msrp_transport.logger.received_chunk_data(data, self.msrp_transport, transaction_id=self.data.transaction_id)
self.msrp_transport._data_write(data, final=False)
def connectionLost(self, reason=connectionDone):
self.msrp_transport._connectionLost(reason)
_re_uri = re.compile("^(?P<scheme>.*?)://(((?P<user>.*?)@)?(?P<host>.*?)(:(?P<port>[0-9]+?))?)(/(?P<session_id>.*?))?;(?P<transport>.*?)(;(?P<parameters>.*))?$")
def parse_uri(uri_str):
match = _re_uri.match(uri_str)
if match is None:
raise ParsingError("Cannot parse URI")
uri_params = match.groupdict()
if uri_params["port"] is not None:
uri_params["port"] = int(uri_params["port"])
if uri_params["parameters"] is not None:
try:
uri_params["parameters"] = dict(param.split("=") for param in uri_params["parameters"].split(";"))
except ValueError:
raise ParsingError("Cannot parse URI parameters")
scheme = uri_params.pop("scheme")
if scheme == "msrp":
uri_params["use_tls"] = False
elif scheme == "msrps":
uri_params["use_tls"] = True
else:
raise ParsingError("Invalid scheme user in URI: %s" % scheme)
if uri_params["transport"] != "tcp":
raise ParsingError('Invalid transport in URI, only "tcp" is accepted: %s' % uri_params["transport"])
return URI(**uri_params)
class ConnectInfo(object):
host = None
use_tls = True
port = 2855
def __init__(self, host=None, use_tls=None, port=None, credentials=None):
if host is not None:
self.host = host
if use_tls is not None:
self.use_tls = use_tls
if port is not None:
self.port = port
self.credentials = credentials
if self.use_tls and self.credentials is None:
from gnutls.interfaces.twisted import X509Credentials
self.credentials = X509Credentials(None, None)
@property
def scheme(self):
if self.use_tls:
return 'msrps'
else:
return 'msrp'
# use TLS_URI and TCP_URI ?
class URI(ConnectInfo):
def __init__(self, host=None, use_tls=None, user=None, port=None,
session_id=None, transport="tcp", parameters=None,
credentials=None):
ConnectInfo.__init__(self, host or host_module.default_ip, use_tls=use_tls, port=port, credentials=credentials)
self.user = user
if session_id is None:
session_id = '%x' % random.getrandbits(80)
self.session_id = session_id
self.transport = transport
if parameters is None:
self.parameters = {}
else:
self.parameters = parameters
def __repr__(self):
params = [self.host, self.use_tls, self.user, self.port, self.session_id, self.transport, self.parameters]
defaults = [False, None, None, None, 'tcp', {}]
while defaults and params[-1]==defaults[-1]:
del params[-1]
del defaults[-1]
return '%s(%s)' % (self.__class__.__name__, ', '.join(`x` for x in params))
def __str__(self):
uri_str = []
if self.use_tls:
uri_str.append("msrps://")
else:
uri_str.append("msrp://")
if self.user:
uri_str.extend([self.user, "@"])
uri_str.append(self.host)
if self.port:
uri_str.extend([":", str(self.port)])
if self.session_id:
uri_str.extend(["/", self.session_id])
uri_str.extend([";", self.transport])
for key, value in self.parameters.iteritems():
uri_str.extend([";", key, "=", value])
return "".join(uri_str)
def __eq__(self, other):
"""MSRP URI comparison according to section 6.1 of RFC 4975"""
if self is other:
return True
try:
if self.use_tls != other.use_tls:
return False
if self.host.lower() != other.host.lower():
return False
if self.port != other.port:
return False
if self.session_id != other.session_id:
return False
if self.transport.lower() != other.transport.lower():
return False
except AttributeError:
return False
return True
def __ne__(self, other):
return not self == other
def __hash__(self):
return hash((self.use_tls, self.host.lower(), self.port, self.session_id, self.transport.lower()))

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